I have a small bit of experience with Congressional hearings (I have been a witness at two) so I wanted to answer a question asked at Engadget after the Facebook hearings:

Throughout the hearings, Congressional leaders repeated questions that had already been asked. We heard them ask again and again whether the company would work with Congress on legislation that would impose regulations on social networks like Facebook and others. We also heard many leaders ask when exactly Facebook learned that Cambridge Analytica had improperly obtained user data. This repetition continued with questions about changes to policy, Facebook's dense terms of service and whether users have been notified if their data were purchased by Cambridge Analytica. If time was so precious to these individuals -- and it should be, four minutes flies by and this is an important topic -- wouldn't they try to avoid repeating the same questions ad nauseam?

I have two answers for this

Congresspersons don't really care what the answer is to these questions. OK, they may care a little, but probably only a little because they seldom leave any time for answers after they are done with their public posturing. What they really care about is that their constituents back home see that they CARE and are DOING SOMETHING about a timely issue of concern to ordinary people. Representative Loony is playing to his local media in East Random, WV. The Representative from East Random doesn't care if four other Representatives have asked the same hard-hitting question. Those other repetitions are not going to show up on the local news in East Random. What is going to show up is Representative Loony asking the question. He will look like he CARES and like he is DOING SOMETHING. He is likely not really concerned that he is mocked in the Washington Post for wasting his questioning time, because no one who is going to vote for him in East Random reads the Washington Post anyway.

Many (but not all) Congresspersons are not that bright. I remember sitting in the committee hearing listening to the questions they were asking me and the other folks testifying and thinking, "how did these folks get here?" I decided the only common denominator had to be pure will. Because they were not all smart, not all charismatic -- not even as a group particularly impressive**. Anyway, whether bright or not, most do not really understand technology and related issues. And so their staffers write their questions for them. And if someone else asks the questions first? Some have the ability to improvise but I can tell you for a fact that for some, all they can do is just proceed and read the questions their staffers gave them.

** Postscript: Ayn Rand used to write that everyone assumes that people in power got that way by beating out everyone else, such that they must be excellent at something. Rand always said this was false, that people in power were the zero where conflicting forces cancelled out. Their being in power (vs. someone else being there) was a happenstance due to external factors and having little to do with that particular individual. I never really understood this the first few times I read it but in modern times I am starting to understand it better. Donald Trump strikes me as following Wesley Mouch's career arc.

The_Big_W:

Matthew Slyfield:

"I have two answers for this"

There is a third possibility, but I wouldn't give most congress critters enough credit to employ this.

Police interrogator will ask suspects the same questions repeatedly. The idea is that the suspect will give slightly different answers each time, and the police can learn important information from the inconsistencies.

irandom419:

I remember a minimum wage(productivity) hearing with the Chappaquiddick killer questioning the Pizza Hut CEO. Any sympathy for the Democrats quickly evaporated. The CEO gave concise logical answers for everything like foot traffic and prices being inversely related.